With respect to the growing importance of this type of good, the present article develops a definition of the term „network good“. The definition is derived in three ways: first explicit definitions as can be found in the literature are presented, second etymology helps to understand the term, and third implicit definitions are drawn out from the existing literature by looking at the specific properties that economic research has found so far. This is the basis for a new explicit definition. It is applied to find a systematization of network goods and to divide two theoretical frameworks in the literature.